1 . Technical Field
The present invention relates to a feed device such as a paper feed device and a recording device such as an ink jet printer including the feed device.
2 . Related Art
Existing recording devices such as printers include a paper feed device (feed device) for automatically feeding paper to a recording unit while separating a plurality of sheets of paper loaded (that is, stacked) in a stacked state one by one so as to continuously perform recording with respect to the plurality of sheets of paper (recording medium) (for example, JP-A-8-91612).
The feed device of JP-A-8-91612 includes a paper feed cassette (loading unit) in which a plurality of sheets of paper can be stacked, a paper feed roller which rotates in a state of being in contact with uppermost sheet of paper of the sheets of paper stacked and delivers the uppermost sheet in a feed direction, and a gate member for preventing double feed of the uppermost sheet of paper and its underlying paper in the feed direction.
In detail, this gate member is configured such that one end side thereof is oscillatorily supported as a fulcrum and the other end side thereof is placed in contact with an outer circumferential surface of the paper feed roller with a predetermined pressure by the energizing force of a compression spring. In addition, an inclined surface is provided in the other end side of the gate member at a location where the front end of a piece of paper delivered by the paper feed roller may collide therewith. If the front end of the paper delivered by the paper feed roller in the feed direction collides with the inclined surface, the gate member, whose inclined surface is pressed by the paper, oscillates against the energizing force of the compression spring in a direction separate from the outer circumferential surface of the paper feed roller and thus a gap through which only a single sheet of paper may pass is formed between the paper feed roller and the gate member. Accordingly, only uppermost sheet of paper is fed through the gap in the feed direction. If the uppermost sheet of paper and its underlying paper are double fed by the friction force therebetween, the double feed of the paper underlying the uppermost sheet of paper is prevented by the inclined surface of the gate member.
However, in such a feed device, in order to ensure friction force for delivering the paper, the outer circumferential surface of the paper feed roller is mostly formed of a soft material such as rubber. Accordingly, as in JP-A-8-91612, if the other end side of the gate member is in contact with the paper feed roller in an energized state, in particular, in the environment in which the temperature or humidity is high, the outer circumferential surface of the paper feed roller may be deformed. In order to press the inclined surface by the paper so as to oscillate the gate member such that a gap through which only a single sheet of paper can pass is formed between the gate member and the outer circumferential surface of the paper feed roller, the contact angle between the delivered paper and the inclined surface of the other end of the gate member is of importance. However, for example, if the outer circumferential surface of the paper feed roller is recessed by the pressing of the gate member such that the contact angle between the paper and the inclined surface is changed, the gap may not be formed with high precision.
In addition, in addition to the paper feed device of the printer, such a problem may generally be generated in a feed device for feeding a plurality of recording mediums stacked while separating the recording mediums.